Fix header comment on SHA1 code.

llvm-svn: 327086
diff --git a/llvm/lib/Support/SHA1.cpp b/llvm/lib/Support/SHA1.cpp
index 20f41c5..3007a78 100644
--- a/llvm/lib/Support/SHA1.cpp
+++ b/llvm/lib/Support/SHA1.cpp
@@ -1,4 +1,4 @@
-//======- SHA1.h - Private copy of the SHA1 implementation ---*- C++ -* ======//
+//====- SHA1.cpp - Private copy of the SHA1 implementation ---*- C++ -* ======//
 //
 //                     The LLVM Compiler Infrastructure
 //